FIELD OF THE INVENTION
The present invention relates to a device for severing a sliver in a filling station of a sliver producing textile machine after a full sliver can has been replaced by an empty one, and in which the filling station comprises a sliver coiling device.
The sliver produced by a textile machine, e.g. by a carding or drawing machine, is delivered into cans in the filling station. Cans of circular cross section are currently used and, in recent years, cans of non-circular cross section are also used. Use of non-circular cans appears to be advantageous especially from the point of view of automation of the production processes in the spinning mills.
When a full can is being replaced by an empty one, it is necessary to sever the sliver between the cans. This can be done for instance, as disclosed in DE OS 38 05 203, which corresponds to U.S. Pat. No. 4,997,738, by stopping the circular, revolving cans when they are full, then moving an arm to the sliver for grasping the sliver, severing it and laying it over the can edge. Alternatively, after partial displacement of the can, the sliver is severed under the can coiler and the sliver then freely falls over the can edge and is then inserted into the sliver holder of the can by means of another device.
Drawbacks of this apparatus are the necessity to interrupt the sliver coiling process, i.e., to stop the can coiler at a predetermined position, at which the arm grasps the sliver, as well as the complicated insertion of the sliver end into the sliver holder of the can.
These drawbacks are partly removed by a method and device according to Czech Patent Application No. 5448-90 in which, after the circular can is filled, the sliver is severed in a similar way and let to hang freely over the can edge. This device is simpler. But, the freely hanging sliver end can be damaged during handling of the cans, and the sliver can be drawn out of the can. Besides, this system cannot be applied to non-circular cans.
As described, for instance, in Czech Patent Application No. 2894-91, the non-circular cans are filled by a known sliver coiling device comprising an instrument for grasping the sliver and having a related mechanism for adapting the sliver end, the instrument being equipped with a mechanism for grasping the sliver between a full non-circular can located in the mechanism for adapting the sliver end and the sliver receiving non-circular can situated in the sliver coiling device. The sliver grasping device at the same time severs the sliver and transfers the thereby produced free end of the sliver from the full non-circular can into a device for creating a reinforced introductory point.
The special drawback of this device is its considerable complexity and the great distance between the sliver end adapting device and the can receiving the sliver, with the resulting difficulty of grasping the sliver.